Temperature
resistance / stability
Dimensional stability
Maintaining
shape and constant dimensions over very long periods of time
are key requirements for insulating materials, particularly
when they are exposed to large variations in temperature (for
example on roofs which can be exposed to both sun and snow, and
within a short period of time).
Because of its thermoset structure, polyurethane exhibits
excellent dimensional stability.
Service temperature
Depending on the density
and type of facings, rigid polyurethane insulation for building
applications can be used long-term over a temperature range
of –30°C to +90°C.
PUR/PIR rigid insulation
materials can withstand temperatures of up to 250°C for
short periods with no adverse effects. PUR/PIR rigid insulation
with mineral fleece facings or without facings is resistant
to hot bitumen and can be used in flat roofing sealed with
bituminous roof covering.
Furthermore, a number
of special polyurethane products can be installed as insulation
under poured-asphalt floor screed and withstand temperatures
of +200°C without additional
heat protection, or can be used for cold-temperature applications
down to –180°C.
